1. a formal religious or public occasion celebrating a particular achievement, milestone, or anniversary
2. the formal activities conducted on a religious or public occasion
3. formal polite behavior; etiquette

Examples

• The graduation ceremony will be held in the auditorium.
• They had a beautiful wedding ceremony in the garden.
• The opening ceremony of the Olympics was spectacular.
• The award ceremony honored outstanding students.
• He stood without ceremony and left the room.
• The funeral ceremony was attended by hundreds of people.
• She dispensed with ceremony and got straight to business.